Hey there fellow Larue enthusiasts.  So I recently got a Larue complete lower from the sale last year from another member.  

From here I was in analysis paralysis shopping for a complete upper to pair with it.

I missed a few of the Primary Arms sales and I honestly wanted a more nostalgic look of the old stealth uppers with a full Quad rail.  So I figured I'd build one instead

So I started hitting the EE and scored a Predatar 16in M4 barrel and then found a Stealth 1.0 upper for sale at Midway which came in this week.  

I noticed the upper and lower don't quite match up.   Is this normal or did they change up possibly the uppers and lowers at some point?  The lock up is solid,  but the lines are more like when using a forged upper on a billet lower.

Totally ascetic but there is a gap in the rear by the upper,  which is small but noticeable.  

I'm still going to piece this together,  but just curious if there were different revisions of uppers and lowers that might match up better?

Oh and I'm still hunting for a 12 or 13.2 quad rail if anyone has any leads.  Best case scenario I find. Stealth DMR upper with the FSB that someone's willing to pay with as that would complete my journey.

Thanks all,

I honestly don’t know when the transition from SMOS to in house machining happened but that could be the difference. IIRC, the old school Stealth uppers, and lt lowers, were smos originally.

If lockup is tight then function will be solid.

FWIW, If you want to tighten things up try a mega upper.Tight as a frog arse.

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My favorite LaRue upper receiver will always be the PredatAR style that is rounded.



The PredatOBR/Ultimate Upper style upper receiver with the 3 flat sides doesn't mate up to the back of the lower receiver as well. On all of mine you can actually see the buffer inside if you hold it at the right angle.

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Thank you all for the replies,  the stealth upper I got from Midway recently is rounded like the predatAR upper above without the tabs for the rail attachment.  

It def is a solid lockup,  and I'm sure will function just fine.  I guess I was expecting more of a fit like the mega upper as that's how I remeber the older uppers.

Enjoy!

This is odd to me. I bought a stripped LT-15 lower from a buddy, and then ordered one of the 16" Match Grade Uppers and LaRue lower parts kit, buffer tube assembly, etc. So I could build an all LaRue rifle.

The upper to lower fit is amazing on mine. I was blown away at how well the receivers fit - better than any "matched" receiver set I've used in the past.

The lock up is for sure tight, not rubber mallet to close tight, but in the back behind the rear pin where the buffer tube sections meet you can def see some light coming through a bit of a gap there holding it just right.

I fully expect this will be a non issue from a functional stand point I was just curious if there's potentially a better fit visually out there on the different revisions of uppers and lowers.  

Hopefully my rail and gas block get here soon I'm getting excited to try it out.

I tried putting a light behind the receivers and see the light you're talking about now. Never noticed that before. I then checked all my ARs (various makes) and my PredatOBR 7.62 - all of them have this.

Good to know,  thanks for checking.

I've got a few of the Stealth 1's and all of them have the gap. Mine are all the rifle feed ramps.

I didn't realize Midway had them and checked it out. They show as m4 feed ramps. Since you have one, are they m4 or rifle ramps?

The one I received does have M4 ramps.